I'm shopping around for CPUs and always see "nm" everywhere. For example, looking at the FX-8120 I see that it is 32nm. Could someone give me a quick 101 breakdown on what that translates to? Thanks like usual TPU.

The lower the more recent and the less heat producing, power consuming its supposed to be. It's like the measure for the size of the die on the cpu. Thwey can shrink it more and more with newer cpu so it cost less in energy.

The nm refers to how many nanometers long the half pitch of a memory cell or transistor gate is. The smaller the process node, the smaller the gates or memory cells are. This means that for the same die area, a smaller process node can pack in more transistors, or the manufacturer can choose to keep the same amount of transistors and reduce the total die area and power consumption of the chip.

Think of transistors as little ball bearings, and you bought a box of a ton of them. The smaller the ball bearings, the more you can cram in the same sized box.

The nm refers to how many nanometers long the half pitch of a memory cell or transistor gate is. The smaller the process node, the smaller the gates or memory cells are. This means that for the same die area, a smaller process node can pack in more transistors, or the manufacturer can choose to keep the same amount of transistors and reduce the total die area and power consumption of the chip.

Think of transistors as little ball bearings, and you bought a box of a ton of them. The smaller the ball bearings, the more you can cram in the same sized box.

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Great analogy and since the bearings are smaller the energy required to move the bearings is less.

The nanometer, shortened to nm, is a measure of how large the transistors are fabricated. By shrinking the fabrication process more transistors can fit in the same area, so CPUs can become more powerful (in a somewhat vague sense).

The problem in shrinking down the fabrication process is two-fold.

First, materials need to change. Think of the electron as a bullet, constantly being fired at a gate; this image is meant to show what a transistor is, a gateway to either allow eletrons to pass or to stop them. A seven meter thick wooden wall will stop the bullet, but as you have less wood the bullet comes closer and closer to penetrating. By shrinking down fabrication, or in the analogy decreasing the wood, you will need a stronger gate material, as well as a weaker bullet (think smaller voltages). Traditionally doped silicon worked for older processes, but Intel and AMD both now use high-k substrates. This technology can allow current manufacturing techniques, but how much longer until it doesn't work is a topic for vigorous debate.

Finally, you don't build a skyscraper the same way you build a garage. The ability for a given architecture to scale as it gets smaller is a real question. If you read up on Bulldozer, you can find out about an experimental new architecture and smaller manufacturing process all in one chip. The problem there is that new architectures often require several revisits before they are successful and mature. New and unique architectures will be needed in the future, so that all those extra transistors can be utilized.

The net result is that smaller processes produce better quality chips in general. There are some exceptions (this may incite flaming, but I think that AMD's Phenom is still superior to Bulldozer), but that rule is generally one to live by.

Note:
Intel has a tick-tock release cycle. They introduce a new architecture, then shrink the die. Subsequently, the next chip will have the same process size as the shrink, but be a new architecture. For reference:

I am looking to upgrade my cpu out of another comp I got but I cannot find it by looking up any series of #'s on the cpu. My friend built the comp im robing parts out off, and he doesn't remember what he used. All I kno is it is an AMD Sempron. By the way im running an almost stock HP a807w. I kno its a dinosaur...